Optical fiber communication network deployments utilize an optical distribution network (ODN) to convey optical signals. As part of a deep fiber optic architecture, remote physical (RPHY) deployment positions use radio frequency (RF) modulation devices deep in the field. RPHY can be attached to coaxial outside plant, while keeping media access control (MAC) and higher layer devices in the center or other location within the network (e.g., at the headend, data center, etc.). RPHY architectures help in improving the efficiency of the network by moving the RF modulation devices closer to customer locations where higher order modulations such as 2K, 4K, etc., quadrature amplitude modulation (QAM) can be implemented. DOCSIS MAC can be physically located at the headend or in datacenter servers where Gigabit to 10G Ethernet interfaces can be deployed between RPHY and the DOCSIS MAC.
However, there are challenges for RPHY architectures. One associated technical challenge involves synchronizing RPHY devices and MAC. Another technical challenge involves the backhaul of large amounts of high-speed Ethernet traffic associated with a backhaul network for RPHY devices since the communication protocol between RPHY and MAC is Ethernet at a rate of multiple Gigabits per second (Gbps).
Another anticipated deployment is the introduction of fifth generation (5G) wireless network services. As part of providing wireless network services, multi-service operators (MSOs) can be contracted by wireless carriers to provide wireless backhaul and/or fronthaul services. The amount of data to backhaul and/or fronthaul for 5G wireless network services is estimated to significantly increase, which poses an additional technical challenge to metro and access networks. RPHY and 5G wireless backhauls and/or fronthauls pose a significant technical challenge to an MSO network design. To design a unified and converged access network to backhaul RPHY and backhaul/fronthaul 5G wireless traffic and at the same time align with an MSO's long term migration direction to passive all-fiber access networks adds further to the technical challenge.
As will be appreciated, there are a number of technical architectural challenges associated with the design of a common DWDM (Dense Wavelength Division Multiplexing) system optimized for RPHY backhaul and 5G or higher iteration mobile wireless fronthaul. For example, one challenge is the coexistence with a variety of passive optical networks (PONs), such as, for example, Gigabit PON (GPON), XGS-PON, Next-Generation PON 2 (NG-PON2), 10G Ethernet PON (10G EPON), 25G PON, etc. on a common ODN. Another challenge is to maintain a passive DWDM infrastructure with at least 20 km fiber reach while compensating for losses from DWDM filters, optical protection switches, coexist filters, etc.